John Leslie may refer to:
- Sir John Leslie (physicist) (1766–1832), Scottish mathematician and physicist
- John Leslie (television presenter) (born 1965), Scottish television presenter of Blue Peter (BBC), Wheel of Fortune and This Morning (both ITV1)
- John Leslie (bishop of Clogher) (1571–1671), Church of Scotland and Church of Ireland bishop
- John Leslie (bishop of Kilmore, Elphin and Ardagh) (1772–1854), Church of Ireland bishop, great-great-grandson of the above
- John Leslie (footballer) (born 1955), English footballer
- John Leslie (politician) (1873–1955), British Labour Party Member of Parliament for Sedgefield, 1935–1950
- John Leslie (pornographic actor) (1945–2010), American porn actor
- John Leslie (rugby union) (born 1970), New Zealand rugby union footballer who played for Scotland
- Sir John Leslie, 1st Baronet of Glaslough, County Monaghan (1822–1916), Conservative Member of Parliament for Co. Monaghan, 1871–1880
- Sir John Leslie, 2nd Baronet of Glaslough (1857–1944), Irish landowner and soldier in the British Army
- Sir John Leslie, 4th Baronet of Glaslough (born 1916)
- John A. Leslie (born 1940), Canadian philosopher
- Jack Leslie (politician) (1920–2010), mayor of Calgary, Alberta
- Shane Leslie, (Sir John Leslie, 3rd Baronet of Glaslough; 1885–1971), Irish writer